When we first built Snapchat, we had a difficult time finding other friends that were using the service. We wanted a way to find friends in our address book that were also using Snapchat – so we created Find Friends. Find Friends is an optional service that asks Snapchatters to enter their phone number so that their friends can find their username. This means that if you enter your phone number into Find Friends, someone who has your phone number in his or her address book can find your username.
A security group first published a report about potential Find Friends abuse in August 2013. Shortly thereafter, we implemented practices like rate limiting aimed at addressing these concerns. On Christmas Eve, that same group publicly documented our API, making it easier for individuals to abuse our service and violate our Terms of Use.
We acknowledged in a blog post last Friday that it was possible for an attacker to use the functionality of Find Friends to upload a large number of random phone numbers and match them with Snapchat usernames. On New Years Eve, an attacker released a database of partially redacted phone numbers and usernames. No other information, including Snaps, was leaked or accessed in these attacks.
We will be releasing an updated version of the Snapchat application that will allow Snapchatters to opt out of appearing in Find Friends after they have verified their phone number. We’re also improving rate limiting and other restrictions to address future attempts to abuse our service.
We want to make sure that security experts can get ahold of us when they discover new ways to abuse our service so that we can respond quickly to address those concerns. The best way to let us know about security vulnerabilities is by emailing us: security@snapchat.com.
The Snapchat community is a place where friends feel comfortable expressing themselves and we’re dedicated to preventing abuse.